My Turn: Clear cutting at odds with stabilizing deer habitat

Posted: Wednesday, January 30, 2008

By LEON SHAUL

A recent Juneau Empire article and an Alaska Public Radio Network story on the sharp decline in deer on northeast Chichagof Island described local hardship but missed a central point while focusing on snow and nonlocal hunters. Deer in northern Southeast are at the bottom of a cycle. The extreme decline in particular areas was caused by an imbalance of two factors: the number of deer at the beginning of winter and the total amount and quality of forage they could reach as the winter progressed.

In the most heavily hunted areas including Douglas Island, high harvest dampens weather-driven cycles, contributing to a more stable population that is less affected by hard winters. Some rural locals may see nonlocal hunters as strictly competition, but their long-term effect may actually be beneficial.

The most important thing that can be done to maintain a stable supply of deer is to manage for a forest that produces a more stable supply of deer food under all weather conditions. The features of such a forest are well-documented in scientific literature but might seem obvious to anyone in the woods. There needs to be enough light reaching the ground to grow forbs and shrubs for the deer to eat, and much of that forage needs to be under trees large enough to intercept snow so deer can reach the food at critical times.

The practice of clear-cut logging is completely at odds with maintaining both of these features over the short- and long-term. Potential forage remains abundant in new clear-cuts, but snow piles up and covers it just when it's needed the most. New trees grow up evenly together and after 25 years or so, their closed canopy shades out the under-story for up to 200 years. Scientists formally refer to this stage as "stem exclusion," although some informally call it the "cellulose cemetery" because of its lack of under-story dependent wildlife. The forest canopy eventually regains an ability to intercept snow but unfortunately there is little benefit without forage to shelter.

Northeast Chichagof Island exhibits both facets of the problem. Public and corporate land is covered with expansive post-1970 clear cuts that remained under several feet of snow last winter. Much of the lower timber on the north side of Tenakee Inlet was clear cut around 1916 and remains dismal deer habitat. In years of lower snowfall, deer are able to feed above the upper extent of old clear cuts. In winters such as 1990-91 and 2006-07, however, when deer leave that area and move to a lower elevation, they must choose between second-growth timber with no forage and open scrub timber where snow blocks access to forage. Most eventually choose a third option, and die on rocky beaches after futilely consuming kelp. One can imagine the more functional forest that existed before, but there's no practical way to reclaim it except to wait yet another century.

In contrast, some sections of Douglas Island that appear at first glance in early photographs to have been clear cut have eventually regenerated into suitable deer habitat. Closer examination of the photos shows a "dog-hair" appearance, as very early loggers who lacked today's chainsaws and more efficient skidding methods left many smaller trees standing out of convenience. When exposed to more light, trees with a head start grew very quickly and became the dominant trees in a mixed-age canopy that today provides some snow interception over a decent under-story.

Clear-cut logging may be the most efficient way to convert trees to cash, but it's the worst possible prescription for maintaining productive deer habitat. People and communities who work to protect remaining mixed-age stands have excellent justification for doing so. It seems that only in years of scarcity like this do we fully appreciate a locally available resource that's considered by many veteran hunters to be the finest eating game animal in the state. There's abundant renewable wood in Southeast, but foresters and policy makers will need to prescribe more selective harvesting methods if we are to maintain stable and abundant deer populations.